the pentagon announced a major expansion in missile defense. >> new defense secretary chuck hagel made the announcement to put more interceptor missiles along the west coast. chris lawrence has more. >> reporter: susan, joe, the pentagon plans to spend up to $1 billion to beef up its civil defense but the big question is, will the missiles actually work? if a nuclear missile is ever fired at the united states, this is the best hope to stop it, 30 interceptor missiles which can be launched from ground sigh lows in alaska and california. now the pentagon is deploying up to 14 more. >> the reason we're doing what we're doing and the reason we're advancing our program here for homeland security is to not take any chances, is to stay ahead of the theret. >> reporter: north korea tested a long range missile in december, it conducted its third nuclear test in february, and just this month, threatened a preemptive nuclear strike on the u.s. that caught the pentagon's attention. >> north korea's shrill public pronouncements underscore the need for the u.s. to continue to take prudent steps to d